Diamond tails, both the same.2+1 Fin set up Flat bottom, Hard edge rails
10-3 foiled and thinner rails in tail area
Nose area thinner foiled on the 10'-3''
The domed deck on 10-3 makes for thinner rails w/ hard edge. 10'-6'' fuller rails and softer edge
The 10'-6'', 7 mile paddle today.